Work on passive immunotherapy of tumors with heterologous antisera of 'directed' specificity is planned to progress from work with long-transplanted lines of L1210, to work with newly-derived tumors. These include spontaneous and radiation-induced lymphomas, sarcomas (radiation-induced, dimethylbenzanthracene-induced, and Moloney sarcoma virus-induced), and carcinomas (dimethylbenzanthracene-induced). The cellular dynamics of the therapy process will be studied by methods that will focus on the whole animal, rather than on in vitro work with restricted numbers of interacting cell populations. Inclusion of chemotherapy, injection of complement and use of membrane-active enzymes are included in the protocol. All work with newly-derived tumors will be done in C57BL/6J mice.